brides of March

Yesterday afternoon, I was shopping in Union Square with a friend when we heard a commotion outside. We peeked out the window and saw a large number of people, both men and women, dressed in (mostly white) wedding dresses, with lots of interesting colorful accessories, like wigs and sunglasses. I was curious, so when we went outside I asked one of the male "brides" why they were dressed up, and he replied, "It's the Brides of March!" I guess there's probably a reference to the Ides of March in there somewhere, but I don't know what it is. Anyway, I was amused.